18216 has 48 divisors (see below), whose sum is σ = 56160. Its totient is φ = 5280.

The previous prime is 18211. The next prime is 18217. The reversal of 18216 is 61281.

18216 = 15³ + 16³ + ... + 18³.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (18211) by changing a digit.

18216 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 781 + ... + 803.

It is an arithmetic number, because the mean of its divisors is an integer number (1170).

2¹⁸²¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28080).

18216 is an abundant number, since it is smaller than the sum of its proper divisors (37944).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18216 is a wasteful number, since it uses less digits than its factorization.

18216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46 (or 39 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 18216 is about 134.9666625504. The cubic root of 18216 is about 26.3118270525.

Adding to 18216 its reverse (61281), we get a palindrome (79497).

The spelling of 18216 in words is "eighteen thousand, two hundred sixteen".